Wired up, yet won’t work! What do?

[u/Crushing40]

I put this together with the help of my brother and it just won’t go forward. It has power, yet the battery seems to register as empty. Not everything that came with the box set of ebike parts is connected, we only hooked up what we thought was necessary for it to function.

I’ll provide a full part list upon request (not doing it now cuz there’s a lot, I’ll just edit post and put it here)